A sample of 200 students at a university was taken after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm.There are 100 students went bar hopping; among them 30 did well in the exam. There are 100 students studied over the weekend; among them 80 students did well.Of those who went bar hopping the weekend before the midterm in the sample, what percent of them did not do well on the midterm?

	A.	15%
	B.	30%
	C.	70%
	D.	80%